The estimated value is believed to be in excess of $10 million and may be the most valuable hoard of gold coins unearthed in North America, according to veteran numismatist Don Kagin.

Kagin, president of numismatic firm Kagin’s Inc. of Tiburon, says the couple want to remain anonymous and plan to sell most of the coins.

Kagin said the gold pieces were struck between 1847 and 1894, many of which are in pristine condition. “This family literally found the pot of gold at the end of the rainbow,” said Kagin said.

The find is now being called The Saddle Ridge Treasure, named after a feature of the family’s property.

After finding the treasure, Kagin Inc. senior numismatist David McCarthy was dispatched to evaluate the coins, according to the press release.

“We all dream about discovering buried treasure; seeing the real thing in person – piles of gold coins encrusted in dirt and rust – the experience was just indescribable,” said McCarthy. “Never in my wildest dreams would I imagine coins coming out of the ground in the kind of condition that I saw in front of me. Many pieces were finer than anything known in major collections or museums.”

Kagin said the previous largest gold coin find in the United States was found in Tennessee in 1985 with coins having a face value of $4,500, eventually selling for around $1 million. The face value of the Saddle Ridge treasure is over $28,000.

About 90 percent of the gold pieces will be available for purchase through Amazon.com, according to Kagin.